# The Effects of Post-Activation Performance Enhancement on High Intensity Interval Training: A Comparison of Traditional and Cluster Set Protocols

PMID: 41785235
Journal: European journal of sport science
Published: 2026 Apr
Authors: Cin M, Saygın Ö, Çabuk R

## Question

Do traditional-set or cluster-set half-squat PAPE protocols improve VO2peak response, time at >=90% VO2max, and total duration during a treadmill HIIT session in trained endurance athletes?

## Summary

In ten well-trained endurance athletes, adding heavy half-squat priming before a treadmill HIIT-to-failure session let athletes run longer and spend more time at or above 90% VO2max. Cluster-set squats performed better than traditional sets for total duration and high-oxygen time, without changing peak VO2, peak heart rate, or perceived exertion.

## Population

- Well-trained endurance athletes in triathlon or middle-/long-distance running
- Sample size: 10
- Age: 23.10 +/- 2.02 years
- Fitness level: VO2max 63.3 +/- 5.1 mL/kg/min; 5.6 +/- 0.8 sessions/week
- Health status: No reported injuries, medication use, or systemic disease

## Methodology

- Randomized crossover acute exercise study
- Five visits completed within 21 days; HIIT sessions separated by 48-96 hours
- Laboratory treadmill and resistance-exercise testing environment
- Randomized and controlled study design.

## Protocol

- Cluster PAPE plus treadmill HIIT.
- Modality: Half back squat followed by treadmill running.
- Work intervals: 1-min run at vVO2max.
- Recovery: 1-min active recovery at 30% vVO2max.
- Sets or repetitions: HIIT repeated to task failure; PAPE 3 sets of 2+2+2 half squats.
- Intensity: 85% 1RM half squat; HIIT at vVO2max.
- Session duration: HIIT averaged 14.4 +/- 1.53 min total duration after cluster PAPE.
- Program length: Acute single-session condition.
- Progression: No progression.
- Control and traditional PAPE.
- Modality: Warm-up only or traditional half squat plus treadmill HIIT.
- Work intervals: 1-min run at vVO2max.
- Recovery: 1-min active recovery at 30% vVO2max.
- Sets or repetitions: Control to failure; traditional PAPE 3 x 6 half squats at 85% 1RM with 120-s rest.
- Intensity: HIIT at vVO2max; traditional squats at 85% 1RM.
- Session duration: Control 12.0 +/- 0.96 min; traditional 13.4 +/- 1.54 min.
- Program length: Acute single-session conditions.
- Progression: No progression.

## Outcomes

### Time near VO2max
Status: improved
Both PAPE protocols increased time at >=90% VO2max, and cluster exceeded traditional.

Overall p<0.001; control 6.21 +/- 0.9 min, traditional 7.43 +/- 1.2 min, cluster 8.11 +/- 1.4 min; cluster vs traditional p=0.005.

### Exercise duration
Status: improved
PAPE increased total exercise and work duration, with cluster longest.

Total exercise duration F(2,18)=23.9, p<0.001; cluster vs traditional p=0.026. Total work duration F(2,18)=31.9, p<0.001; cluster vs traditional p=0.043.

### VO2peak
Status: no clear change
Peak oxygen uptake during HIIT did not differ between control, traditional, and cluster conditions.

F(2,18)=1.8, p=0.198; control 62.3 +/- 5.1, traditional 61.6 +/- 4.0, cluster 61.9 +/- 3.7 mL/kg/min.

### RPE
Status: no clear change
Perceived exertion at task failure was similar across protocols.

p=0.846.

### HR and lactate
Status: mixed
HRpeak and maximal lactate were not significantly different overall, while pre-HIIT lactate was higher after both PAPE protocols.

HRpeak p=0.118; maximal lactate p=0.086; pre-HIIT lactate p<0.001.

## Practical Insights

- For trained athletes, a heavy squat cluster-set primer may increase the high-oxygen stimulus of a 1:1 HIIT session.
- This is not a beginner protocol because it combines heavy squats and treadmill running to failure.

## Limitations

- Small sample of 10 trained athletes
- Acute crossover only
- Long-term training adaptations not measured
- Requires heavy squat experience and laboratory intensity prescription

## Safety And Adherence

- No adverse events reported in extracted text.
- Trained spotters supported the barbell during squat protocols.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41785235/) (pubmed)
- [DOI](https://doi.org/10.1002/ejsc.70152) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12962404/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.